THE CODE DIRECTORY

Diagnostic code references — Page 83.

Browse canonical reference entries. Each definition keeps its own source and vehicle-applicability limits.

Generic OBD-II

P250C

These are code references, not a list of confirmed faults on every vehicle. Read the source and applicability notes, then match the exact vehicle, year, engine and scan report.

Hyundai oil-level circuit-low warning and ROM matching

Engine Oil Level Sensor Circuit High

Engine Oil Level Sensor Circuit Intermittent/Erratic

Venue oil-level warning: the dipstick decides the branch

ECM relay faults can mean power ends too late or too early

ECM/PCM Power Relay Sense Circuit Intermittent

Event Data Recorder Request Circuit/ Open

Event Data Recorder Request Circuit Low

Event Data Recorder Request Circuit High

A/C Refrigerant Pressure Sensor B Circuit

Low-side refrigerant pressure must respond after compressor start

Low-side refrigerant sensor voltage is below its valid range

High refrigerant sensor voltage has its own sample and trip logic

A/C Request A Circuit

PTO Enable Switch Circuit/Open

PTO Enable Switch Circuit Low

PTO Enable Switch Circuit High

PTO Engine Shutdown Circuit/Open

PTO Engine Shutdown Circuit Low

PTO Engine Shutdown Circuit High

A/C Request A Circuit Low

A/C Request A Circuit High

A/C Request B Circuit

A/C Request B Circuit Low

A/C Request B Circuit High

Vacuum Reservoir Pressure Sensor Circuit

Vacuum Reservoir Pressure Sensor Circuit Range/Performance

Vacuum Reservoir Pressure Sensor Circuit Low

Vacuum Reservoir Pressure Sensor Circuit High

Vacuum Reservoir Pressure Sensor Circuit Intermittent

The DME loses communication with the oil-condition sensor

Engine Oil Quality Sensor Circuit Range/Performance

Engine Oil Quality Sensor Circuit Low

Engine Oil Quality Sensor Circuit High

Engine Oil Quality Sensor Circuit Intermittent/Erratic

Diesel oil level too high, dilution and reset history

Mazda CX-50 Hybrid startup failure and campaign eligibility

Ignition Switch Run Position Circuit Low

Ignition Switch Run Position Circuit High

Why an ignition-state fault can appear in throttle supervision

Transmission controller sees run/crank low while the ECM reports it active

Run/start input stays high after the reported run/crank state becomes inactive

Transmission controller sees accessory input disagree with power mode

Accessory-line voltage disagrees with the wakeup state

accessory-input diagnosis includes the network power-mode state

Transit KOEO self-test code versus a running-engine fault

PTO Sense Circuit/Open

PTO Sense Circuit Range/Performance

PTO Sense Circuit Low

Ram PTO-sense high and the AS69RC software case

PTO Sense Circuit Intermittent/Erratic

Oil deterioration inferred from dilution and pressure change

Low-pressure fuel performance after running dry or filter service

low fuel-pressure sensor voltage is not a direct low-pressure measurement

A high electrical signal from the low-pressure fuel sensor

the VAG G410 interpretation includes fuel-supply restriction

Transmission torque-request messages fail validity checks

Torque Management Request Input Signal A Range/Performance

Torque Management Request Input Signal A Low

Torque Management Request Input Signal A High

Performance-launch torque message fails an integrity check

Torque Management Request Input Signal B Range/Performance

PTO Speed Selector Sensor/Switch 1 Circuit/Open

PTO Speed Selector Sensor/Switch 1 Range/Performance

PTO Speed Selector Sensor/Switch 1 Circuit Low

PTO Speed Selector Sensor/Switch 1 Circuit High

PTO Speed Selector Sensor/Switch 1 Circuit Intermittent/Erratic

Hybrid hood switch faults arise when the two signals agree

Torque Management Request Input Signal B Low

Torque Management Request Input Signal B High

Throttle/Fuel Inhibit A Circuit

Throttle/Fuel Inhibit A Circuit Range/Performance

Throttle/Fuel Inhibit A Circuit Low

Throttle/Fuel Inhibit A Circuit High

a coolant-level label can lead to the N493 temperature-control circuit

Engine Coolant Level Sensor/Switch Circuit Range/Performance

Engine Coolant Level Sensor/Switch Circuit Low

Engine Coolant Level Sensor/Switch Circuit High

PTO Speed Selector Sensor/Switch 2 Circuit/Open

PTO Speed Selector Sensor/Switch 2 Range/Performance